Sadly a lot of characters with large hit boxes are candy to range characters especially Marquis. I play quite a bit of Kleese when I don’t feel like playing Mike and when they have a Marquis I’m usually shut down alot. Not a whole lot can be done from my end, it’s more relying on my team to harass him to keep him under control and not kill me in 4 shots.
I have not played toby, but I have played against and with very good tobys, so I don’t know how good my advice will be.
1). I have played against very good, sometimes aimbotting marquis’s, and I find the general strategy to employ against him is to only engage the lane when your shield is up (non-ability shield) as marquis and anyone else for that matter cannot crit you when your shield is up.
2). Play the lane not the versus. Toby has probably the best long range lane control in the game. Kill the minions and harass the enemy battleborn out of lane so your teammates can push up, and take care of the enemy sniper. This is especially true of Marquis. If you force his teammates out of lane and he now has to lane clear, he is no longer shooting at you.
3). Dealing with thorn is a bit of a different beast, as her wave clear allows her to clear and shoot at you at the same time. I have played the thorn vs. toby matchup from thorns point of view, and let me just say this: Toby is a better sniper than her. I am not saying she is a worse character, but toby can out range because his shots fly faster, straighter, and are easier to crit. This may come down to reaching the skill ceiling or not with aiming toby’s projectiles, but at range toby can snipe thorn better than she can snipe him. Close-midrange is another story, but at that point your teammmates need to punish her for coming out of position.
Finally, all I can say is pay attention to your team comp. If you’re the primary wave clearer, you might have a hard time put pressure on the enemy team, which will require you to play much more conservatively. Don’t pick toby if noone on your team is a solution to marquis or thorn.
Well hope my advice can be helpful.